Among his current cases was an investigation into fundraising by New York mayor Bill de Blasio, as well as a sexual harassment case against Fox News by its employees.

After it was reported on Saturday that he had refused to resign, top New York Republican Brian Kolb tweeted: "Good for Preet, he is doing the job he was appointed to do!"

On Saturday, New York Attorney General Eric Schneiderman said in a statement: "President Trump's abrupt and unexplained decision to summarily remove over 40 US attorneys has once again caused chaos in the federal government."

"Preet Bharara, like many of the US attorneys dismissed this week, served with honour and distinction."

However, ex-Republican strategist Brian Walsh argued that the firing was "nothing new" as "US attorneys serve at the pleasure of the [president] - even Preet".

Mr Bharara's office and the Justice Department refused to comment further, according to the Associated Press.